Light-Generating Arrangement

ABSTRACT

The invention relates to a light-generating arrangement comprising a light-emitting semiconductor element provided with electric supply lines and a transparent light-directing element ( 2 ) which is arranged upstream of the semiconductor element in the emission direction at a distance therefrom and which is used for concentrating the light emitted by said semiconductor element in such a way that a light stream is formed. The light output surface ( 4 ) of the light-directing element ( 2 ) comprises a microstructure ( 6 ) consisting of a plurality of elevations and cavities deviating the trajectory of the light stream by &lt;5°.

The invention relates to a light-generating arrangement comprising a light-emitting semiconductor element having electrical supply lines, and comprising a transparent light-orienting element arranged in front of the semiconductor element at a distance in the emission direction, by means of which light-orienting element the light emitted by the semiconductor element can be concentrated to form a luminous flux.

Light-emitting semiconductor elements, in particular high-power LEDs, usually have a lambertian emitting characteristic or a very large aperture angle of the emission characteristic. In order to obtain a directional emission, primarily refractive and reflective secondary optics are used as light-orienting element in the case of the high-power LEDs. Said optics lead to a concentration of the luminous flux and to very high luminances in the forward direction.

A significant inhomogeneity of the luminous flux occurs as a result of the structure of the semiconductor elements, in particular also as a result of their electrical supply lines and contact connections.

When a plurality of LED chips are used in an array, the positioning of the individual chips is reflected in the brightness distribution of the luminous flux.

Furthermore, if LED chips of different colors are used then the mixing of the individual color components is usually incomplete. Significant color variations can therefore be observed over the width of the luminous flux.

These influences on the luminous flux are very disturbing and restrict the use of such light-generating arrangements.

Therefore, it is an object of the invention to provide a light-generating arrangement of the type mentioned in the introduction which avoids the disadvantages mentioned and the luminous flux of which is highly homogeneous and does not have a substantial loss of brightness.

This object is achieved according to the invention by virtue of the fact that the coupling-out surface of the light-orienting element has a microstructure formed from a multiplicity of elevations and depressions, by means of which microstructure the beam paths of the luminous flux can be deflected by an angle of <5°.

In a further solution, this object is achieved by virtue of the fact that the wall of the light-orienting element that extends from the coupling-in surface to the coupling-out surface of the light-orienting element has a microstructure formed from a multiplicity of elevations and depressions, by means of which microstructure the reflection of the beam paths of the luminous flux at the wall of the light-orienting element can be deflected by an angle of <5°.

By means of the light-orienting element forming a secondary optical element, the light emitted in all directions by the semiconductor element is inherently directed and emitted as directional luminous flux.

By means of the microstructure, the individual beam paths of the directed light beams of the luminous flux are slightly changed in such a way that although the light is newly distributed within the luminous flux, which can be a light cone after emission, this occurs in such a way that essentially no light backscatters or is scattered out of the luminous flux or light cone.

The light-orienting element can preferably be a converging lens.

A high uniformity of the luminous flux is achieved by virtue of the fact that the microstructure has a peak-to-value height of <100 μm.

If the light-orienting element is a plastic injection-molded part having the microstructure integrally formed on its coupling-out surface and/or on its wall, then it is possible, by means of the injection mold being formed in a corresponding manner, for the microstructure to be concomitantly produced in a cost-effective manner during the production of the light-orienting element.

However, it is also possible for the microstructure to be formed on a transparent film that is fixed on the coupling-out surface by means of a refractive-index-matched adhesive.

A further, likewise simple measure for producing the microstructure consists in the fact that the microstructure is formed by means of a resist which is applied to the coupling-out surface and/or the wall of the light-orienting element and the free surface of which assumes the microstructure upon curing.

A good homogenization of the luminous flux without scattering in the actual sense is achieved by virtue of the fact that the microstructure is formed by a multiplicity of microlenses or microlens-like elevations arranged in a distributed manner on the coupling-out surface and/or on the wall of the orienting element.

The elevations and depressions are preferably arranged in a stochastically distributed manner.

An exemplary embodiment of the invention is illustrated in the drawing and is described in more detail below. The single FIGURE of the drawing shows a schematic cross-sectional illustration of a light-generating arrangement.

The light-generating arrangement illustrated has a high-power LED (light-emitting diode) 1 as light-emitting semiconductor element, a light-orienting element 2 being arranged in front of said LED at a distance in the light emission direction.

The light-orienting element 2 forming a secondary optical element is produced from a transparent plastic as an injection-molded part.

The undirected light emitted by the high-power LED is introduced into the light-orienting element 2 at a coupling-in surface 3 thereof and is oriented inter alia by reflection at the wall 5 of the light-orienting element 2, said wall extending from the coupling-in surface 3 to a coupling-out surface 4 of the light-orienting element 2, to form a luminous flux which emerges homogeneously and directionally at the coupling-out surface 4.

The coupling-out surface 4 has a microstructure 6 composed of a multiplicity of non-uniform elevations and depressions, by means of which the beam paths of the oriented luminous flux, upon emerging from the light-orienting element 2, are deflected by an angle of <5°.

The directional luminous flux is thus maintained to the greatest possible extent. The beam paths are only slightly altered, which leads to a homogenization of the luminous flux.

Instead of the arrangement of the microstructure 6 on the coupling-out surface 4, the microstructure could also be arranged on the wall 5.

This would have the effect that although the beam paths would be reflected for their orientation, in addition said beam paths would also be deflected by an angle of <5° by the microstructure, whereby the directional luminous flux would acquire a homogenization. 

1-9. (canceled)
 10. A light-generating arrangement comprising: a light-emitting semiconductor element having electrical supply lines; and a transparent light-orienting element arranged in front of the light-emitting semiconductor element at a distance in a direction of light emission, said light-orienting element concentrating the light emitted by the light-emitting semiconductor element to form a directional luminous flux; wherein a coupling-out surface of the light-orienting element has a microstructure formed from a multiplicity of elevations and depressions, said microstructure deflecting individual beam paths of directed light beams of the luminous flux by an angle of <5°.
 11. The light-generating arrangement as claimed in claim 10, wherein the light-orienting element is a converging lens.
 12. The light-generating arrangement as claimed claim 10, wherein the microstructure has a peak-to-value height of <100 μm.
 13. The light-generating arrangement as claimed in claim 11, wherein the microstructure has a peak-to-value height of <100 μm.
 14. The light-generating arrangement as claimed in claim 10, wherein the light-orienting element is a plastic injection-molded part having the microstructure integrally formed on the coupling-out surface.
 15. The light-generating arrangement as claimed in claim 10, wherein the microstructure is formed on a transparent film and fixed on a coupling-out surface by a refractive-index-matched adhesive.
 16. The light-generating arrangement as claimed in claim 11, wherein the microstructure is formed on a transparent film and fixed on a coupling-out surface by a refractive-index-matched adhesive.
 17. The light-generating arrangement as claimed in claim 12, wherein the microstructure is formed on a transparent film and is fixed on a coupling-out surface by a refractive-index-matched adhesive.
 18. The light-generating arrangement as claimed claim 10, wherein the microstructure is formed by a resist which is applied to at least one of a coupling-out surface and the wall of the light-orienting element, a free surface of which assumes a shape of the microstructure upon curing.
 19. The light-generating arrangement as claimed claim 11, wherein the microstructure is formed by a resist which is applied to at least one of a coupling-out surface and a wall of the light-orienting element, a free surface of which assumes a shape of the microstructure upon curing.
 20. The light-generating arrangement as claimed claim 12, wherein the microstructure is formed by a resist which is applied to at least one of a coupling-out surface and a wall of the light-orienting element, a free surface of which assumes a shape of the microstructure upon curing.
 21. The light-generating arrangement as claimed in claim 10, wherein the microstructure is formed by a multiplicity of microlenses or microlens-like elevations arranged in a distributed manner on at least one of a coupling-out surface and a wall of the light-orienting element.
 22. The light-generating arrangement as claimed in claim 10, wherein the elevations and depressions are arranged in a stochastically distributed manner.
 23. A light-generating arrangement comprising: a light-emitting semiconductor element having electrical supply lines; and a transparent light-orienting element arranged in front of the light-emitting semiconductor element at a distance in the emission direction, said light-orienting element concentrating light emitted by the light-emitting semiconductor element to form a directional luminous flux; wherein a wall of the light-orienting element, which extends from the coupling-in surface to the coupling-out surface of the light-orienting element, has a microstructure formed from a multiplicity of elevations and depressions, said microstructure deflecting a reflection of individual beam paths of directed light beams of the luminous flux at the wall of the light-orienting element by an angle of <5°.
 24. The light-generating arrangement as claimed in either of claim 23, wherein the light-orienting element is a converging lens.
 25. The light-generating arrangement as claimed in one of claim 23, wherein the microstructure has a peak-to-value height of <100 μm.
 26. The light-generating arrangement as claimed in one of claim 24, wherein the microstructure has a peak-to-value height of <100 μm.
 27. The light-generating arrangement as claimed in one claim 24, wherein the light-orienting element is a plastic injection-molded part having the microstructure integrally formed on the wall of the light-orienting element.
 28. The light-generating arrangement as claimed in claim 23, wherein the microstructure is formed on a transparent film and fixed on a coupling-out surface by a refractive-index-matched adhesive.
 29. The light-generating arrangement as claimed in claim 24, wherein the microstructure is formed on a transparent film and fixed on a coupling-out surface by a refractive-index-matched adhesive.
 30. The light-generating arrangement as claimed in claim 25, wherein the microstructure is formed on a transparent film and fixed on a coupling-out surface by a refractive-index-matched adhesive.
 31. The light-generating arrangement as claimed in claim 23, wherein the microstructure is formed by a resist which is applied to at least one of a coupling-out surface and the wall of the light-orienting element, a free surface of which assumes a shape of the microstructure upon curing.
 32. The light-generating arrangement as claimed in claim 24, wherein the microstructure is formed by a resist which is applied to at least one of a coupling-out surface and the wall of the light-orienting element, a free surface of which assumes a shape of the microstructure upon curing.
 33. The light-generating arrangement as claimed in claim 25, wherein the microstructure is formed by a resist which is applied to at least one of a coupling-out surface and the wall of the light-orienting element, a free surface of which assumes a shape of the microstructure upon curing.
 34. The light-generating arrangement as claimed in claim 25, wherein the microstructure is formed by a multiplicity of microlenses or microlens-like elevations arranged in a distributed manner on at least one of a coupling-out surface and a wall of the light-orienting element.
 35. The light-generating arrangement as claimed in claim 23, wherein the elevations and depressions are arranged in a stochastically distributed manner. 